The present invention is directed toward flexible bulk containers and more particularly toward slide fasteners for use with the filling and discharge spouts of the container.
Large, flexible fabric bags for containing and transporting granular or powdered bulk material have been used for many years and their use is becoming increasingly more popular. This is primarily due to their relatively low cost and to the fact that when the bags are empty they take up very little space and are relatively light. When filled, the flexible bulk containers may carry a cubic meter or more of material and may weigh in excess of two tons. The containers are normally provided with straps or the like adjacent the top thereof so that the containers can be transported by forklift trucks or the like. Containers of this type are shown, for example, in U.S. Pat. Nos. 4,010,784; 4,081,011; 4,300,608; 4,301,848 and in British Application No. GB 2,063,816 A published June 10, 1981.
The fill and discharge spouts of the containers are normally comprised of a flexible material similar to the material from which the containers themselves are made. These spouts are substantially tubularly shaped when they are in their full open position and are normally closed by simply tying a cord therearound. Most commonly, the cord is permanently attached to the spout by having a centrally located portion thereof sewn to the spout. The conventional method for securing the cord to the spout is simply by tying a knot in the same.
U.S. Pat. Nos. 4,081,011; 4,300,608 and 4,301,848 show examples of bulk containers utilizing cords and knots for closing the spouts thereof.
Although flexible bulk containers are relatively inexpensive, they are intended to be reusable. Thus, when it is necessary to open a spout, it is desirable to untie the knot which had been made in the cord. Unfortunately, this is not always easy to do especially with respect to the discharge spout. The problem with the discharge spout is that a workman would have to be standing under the container which may have two tons of material therein while he is attempting to untie the knot. It is not uncommon, therefore, for workmen to merely cut the cord or the spout with a knife to open the same. If the container itself is cut, it becomes worthless and must be discarded. If the cord is cut, a new cord must be sewn or otherwise attached to the spout before the container can be used again.